Craven Street and the Strand from Duncannon Street junction to Trafalgar Square was closed.

Credit: PA

High levels of natural gas were detected at Craven Street, London Fire Brigade said.

Brett Loft, LFB spokesman and station manager at Chelsea, said: "It has happened a few times recently.

"With the ageing pipes in London there is an ongoing programme at the moment to replace all the pipework."

A Network Rail spokesman said: "Having received the all-clear from the emergency services, we've now reopened Charing Cross and Waterloo East stations and are working with Southeastern to get services back up and running as quickly as possible."

Charing Cross is London's fifth busiest station, used by about 42 million passengers a year.

The Strand, a major route through central London, was closed and a 165-yard (150 metre) cordon put in place while National Grid engineers tried to isolate the leak.

The Strand was closed as National Grid engineers tried to isolate the leak. Credit: ITV News